Array Intersect and Array union in PHP

Array Intersect

<?php

$array1 = array(2, 4, 6, 8, 10, 12);
$array2 = array(1, 2, 3, 4, 5, 6);

echo "<pre>";
print_r(array_intersect($array1, $array2));
echo "</pre>";
echo "<pre>";
print_r(array_intersect($array2, $array1));
echo "</pre>";

?>


// output

Array
(
    [0] => 2
    [1] => 4
    [2] => 6
)


Array
(
    [1] => 2
    [3] => 4
    [5] => 6
)

Array Union

<?php
$a = array(1,2,3,4);
$b = array(2,4,5,6);

//  $a = 1 2 3 4
$union =                            //  $b =   2   4 5 6
        array_merge(
          array_intersect($a, $b),    //         2   4
          array_diff($a, $b),         //       1   3
          array_diff($b, $a)          //               5 6
        );                              //  $u = 1 2 3 4 5 6
?>


// Output

Array
(
    [0] => 2
    [1] => 4
    [2] => 1
    [3] => 3
    [4] => 5
    [5] => 6
)